<< I understand your point, but Sharp himself said "there is no exception
or instance of the like mode of expression, that I know of, which
necessarily requires a construction different from what is here laid
down, EXCEPT the nouns be proper names, or in the plural number; in
which case there are many exceptions."

The very fact that Sharp said that plurals were EXCEPTIONS to the rule
shows he did not exclude them from the rule otherwise they could not
be considered exceptions.

Today folks are careful to state "Sharp's" rule like the following,
which makes it appear that there are no exceptions to the rule when in
fact Sharp said there were.

1. both are personal
2. both are singular
3. both are non-proper (i.e., common terms, not proper names)
4. neither are quasi-proper names.

Smart's is a superior rule in that it does not have arbitrary or
contrived exceptions, and that was my point. However I will grant that
Sharp did understand that plurals were an exception to his rule and
that this was not discovered by someone other than Sharp. Of course,
the same cannot be said for quasi-proper names. >>

First, what are quasi-proper names (examples?) and who has argued for these
as exceptions? Second, you have misunderstood Sharp's methodology. He was
articulating the rule in a general sense in order to determine in what cases
it was valid and what cases it was not. Thus, he was methodologically
refining the rule to its final form. Third, nouns separated by KAI normally
have different referents. Sharp was identifying a lingiuistic phenomenon that
went against the norm. Fourth, the exceptions are neither contrived nor
arbitrary; they are common sense. Different proper names do not refer to the
same person. Groups usually do not have the same referent. The same goes with
impersonal nouns. Remember, this is a linguistic phenomenon that goes against
the norm, and consistently goes against it. All Sharp's rule does is
articulate what is the norm and to be expected. There may or may not be
exceptions to the norm.